1.1 ,This test method is applicable to determine the pH of water samples with a conductivity of 2 to 100 μ,S/cm over the pH range of 3 to 11 and is frequently used in power generation low conductivity samples. pH measurements of water of low conductivity are problematic. Specifically, this test method avoids contamination of the sample with atmospheric gases and prevents volatile components of the sample from escaping. This test method provides for pH electrodes and apparatus that address additional considerations discussed in Annex A2. This test method also minimizes problems associated with the sample's pH temperature coefficient when the operator uses this test method to calibrate an on-line pH monitor or controller (see Appendix X1).